Electrophysiological Signatures of Visual Lexical Processing: Open-and Closed-Class Words

An ERP study on verb bias and thematic role assignment in standard Indonesian

This study investigates the effects of verb bias on sentence comprehension in Standard Indonesian (SI), a language where the passive construction is frequent and salient. We examined the hypothesis that lexical biases influence processing efforts. To disentangle effects of verb bias from structural effects, we held structure constant by using only passive sentences in our event-related potential (ERPs) experiment. Using an SI corpus, we identified verbs more frequently used in passive sentences ("passive-bias verbs") and those more frequently used in active ones ("active-bias verbs") to form passive sentences. Cluster-based permutation tests revealed significant differences between conditions. In the postverbal region (adverb), passive sentences with active-bias verbs elicited a broadly distributed negative shift that corresponded to the N280 distribution, a component associated with grammatical processing complexity. This suggests that active-bias verbs in passive contexts impose greater processing demands than their passive-bias counterparts, reflecting the integration of verb-specific preferences with sentence structure. These findings highlight how verb bias influences sentence comprehension and provide insights into cross-linguistic differences. In languages with predominantly active-bias verbs, using them in passive constructions may amplify processing costs. This study shows the importance of lexical biases and structural preferences in shaping sentence processing, contributing to a broader understanding of the interaction between lexical and syntactic factors in language comprehension.

Brain imaging and electrophysiological markers of anaphoric reference during speech production

Pronouns create cohesive links in discourse by referring to previously mentioned elements. Here, we focus on pronominalization during speech production in three experiments employing ERP and fMRI methodologies. Participants were asked to produce two short sentences describing a man or woman using an object. In the second sentence, they were instructed to use a pronoun to refer to the same person and a noun to refer to a different person. The first ERP experiment revealed that noun conditions elicited more negative ERPs starting at 220 ms, with significant differences in early and later time windows, particularly in the left hemisphere. The second ERP experiment showed divergence at 280 ms, with significant differences between 300 and 400 ms at midline electrodes, again indicating more negative ERPs for nouns. The fMRI experiment identified greater activations for nouns than pronouns in regions like the superior temporal gyrus (STG) and cerebellar vermis, suggesting higher working memory load and lexical retrieval demands for nouns compared to pronouns. Moreover, pronouns elicited an enhanced centro-parietal positivity, indicating increased attentional demands. These findings suggest that while noun processing requires greater working memory and lexical retrieval, pronoun processing engages more attentional resources. This study advances our understanding of the neural mechanisms underlying pronominalization during speech production, highlighting distinct neural responses for nouns and pronouns.

Understanding words in context: A naturalistic EEG study of children's lexical processing

When listening to speech, adults rely on context to anticipate upcoming words. Evidence for this comes from studies demonstrating that the N400, an event-related potential (ERP) that indexes ease of lexical-semantic processing, is influenced by the predictability of a word in context. We know far less about the role of context in children's speech comprehension. The present study explored lexical processing in adults and 5-10-year-old children as they listened to a story. ERPs time-locked to the onset of every word were recorded. Each content word was coded for frequency, semantic association, and predictability. In both children and adults, N400s reflect word predictability, even when controlling for frequency and semantic association. These findings suggest that both adults and children use top-down constraints from context to anticipate upcoming words when listening to stories.

Linguistic and emotional responses evoked by pseudoword presentation: An EEG and behavioral study

When the semantic properties of words are turned off, such as in pseudowords, the grammatical properties of the stimuli indicated through suffixes may provide cues to the meaning. The application of electroencephalography (EEG), combined with the pseudoword paradigm, allows for evaluating the effects of verbs and nouns as linguistic categories within the time course of processing. To contribute to the ongoing discussion regarding the functional processing of words from different grammatical classes, we conducted an EEG experiment, followed by a behavioral lexical decision task (LDT). The EEG and LDT indicated different neural and behavioral reactions to the presented grammar classes, allowing for a deeper understanding of the neuro- and psycholinguistic dimensions of grammar.

Electrophysiological Evidence Reveals the Asymmetric Transfer from the Right to Left Hemisphere as Key to Reading Proficiency

The present investigation aimed to explore the interhemispheric interactions that contribute to changes in reading proficiency by examining the processing of visual word recognition in relation to word familiarity. A lexical decision task was administered to 25 participants, and their electrophysiological activity was recorded. A behavioral analysis showed the faster and more accurate processing of highly familiar words compared to less familiar ones. An event-related potential analysis uncovered an asymmetric familiarity effect over the N100 and N400 components across the two hemispheres, indicating an asymmetrical word familiarity processing. Granger causality analyses demonstrated a stronger transfer of information from the right hemisphere (RH) to the left hemisphere (LH) during the N100 processing and a weaker transfer from the LH to the RH during the N400 processing for highly familiar word recognition. These findings suggest that the asymmetric coordination between the RH and LH occurs early in visual word recognition and highlight the importance of interhemispheric interactions in efficient visual word recognition and proficient reading.

ERPs Reveal How Semantic and Syntactic Processing Unfold across Parafoveal and Foveal Vision during Sentence Comprehension

We examined how readers process content and function words in sentence comprehension with ERPs. Participants read simple declarative sentences using a rapid serial visual presentation (RSVP) with flankers paradigm. Sentences contained either an unexpected semantically anomalous content word, an unexpected syntactically anomalous function word or were well formed with no anomalies. ERPs were examined when target words were in the parafoveal or foveal vision. Unexpected content words elicited a typically distributed N400 when displayed in the parafovea, followed by a longer-lasting, widely distributed positivity starting around 300 ms once foveated. Unexpected function words elicited a left lateralized LAN-like component when presented in the parafovea, followed by a left lateralized, posteriorly distributed P600 when foveated. These results suggested that both semantic and syntactic processing involve two stages-the initial, fast process that can be completed in parafovea, followed by a more in depth attentionally mediated assessment that occurs with direct attention.

Neural correlates of word representation vectors in natural language processing models: Evidence from representational similarity analysis of event-related brain potentials

Natural language processing models based on machine learning (ML-NLP models) have been developed to solve practical problems, such as interpreting an Internet search query. These models are not intended to reflect human language comprehension mechanisms, and the word representations used by ML-NLP models and human brains might therefore be quite different. However, because ML-NLP models are trained with the same kinds of inputs that humans must process, and they must solve many of the same computational problems as the human brain, ML-NLP models and human brains may end up with similar word representations. To distinguish between these hypotheses, we used representational similarity analysis to compare the representational geometry of word representations in two ML-NLP models with the representational geometry of the human brain, as indexed with event-related potentials (ERPs). Participants listened to stories while the electroencephalogram was recorded. We extracted averaged ERPs for each of the 100 words that occurred most frequently in the stories, and we calculated the similarity of the neural response for each pair of words. We compared this 100 × 100 similarity matrix to the 100 × 100 similarity matrix for the word pairs according to two ML-NLP models. We found significant representational similarity between the neural data and each ML-NLP model, beginning within 250 ms of word onset. These results indicate that ML-NLP systems that are designed to solve practical technology problems have a representational geometry that is correlated with that of the human brain, presumably because both are influenced by the structural properties and statistics of language.

Differential temporo-spatial pattern of electrical brain activity during the processing of abstract concepts related to mental states and verbal associations

Refined grounded cognition accounts propose that abstract concepts might be grounded in brain circuits involved in mentalizing. In the present event-related potential (ERP) study, we compared the time course of neural processing in response to semantically predefined abstract mental states and verbal association concepts during a lexical decision task. In addition to scalp ERPs, source estimates of underlying volume brain activity were determined to reveal spatio-temporal clusters of greater electrical brain activity to abstract mental state vs. verbal association concepts, and vice versa. Source estimates suggested early (onset 194 ms), but short-lived enhanced activity (offset 210 ms) to verbal association concepts in left occipital regions. Increased occipital activity might reflect retrieval of visual word form or access to visual conceptual features of associated words. Increased estimated source activity to mental state concepts was obtained in visuo-motor (superior parietal, pre- and postcentral areas) and mentalizing networks (lateral and medial prefrontal areas, insula, precuneus, temporo-parietal junction) with an onset of 212 ms, which extended to later time windows. The time course data indicated two processing phases: An initial conceptual access phase, in which linguistic and modal brain circuits rapidly process features depending on their relevance, and a later conceptual elaboration phase, in which elaborative processing within feature-specific networks further refines the concept. This study confirms the proposal that abstract concepts are based on representations in distinct neural circuits depending on their semantic feature content. The present research also highlights the importance of investigating sets of abstract concepts with a defined semantic content.

Prediction of Second Language Proficiency Based on Electroencephalographic Signals Measured While Listening to Natural Speech

This study had two goals: to clarify the relationship between electroencephalographic (EEG) features estimated while non-native speakers listened to a second language (L2) and their proficiency in L2 determined by a conventional paper test and to provide a predictive model for L2 proficiency based on EEG features. We measured EEG signals from 205 native Japanese speakers, who varied widely in English proficiency while they listened to natural speech in English. Following the EEG measurement, they completed a conventional English listening test for Japanese speakers. We estimated multivariate temporal response functions separately for word class, speech rate, word position, and parts of speech. We found significant negative correlations between listening score and 17 EEG features, which included peak latency of early components (corresponding to N1 and P2) for both open and closed class words and peak latency and amplitude of a late component (corresponding to N400) for open class words. On the basis of the EEG features, we generated a predictive model for Japanese speakers’ English listening proficiency. The correlation coefficient between the true and predicted listening scores was 0.51. Our results suggest that L2 or foreign language ability can be assessed using neural signatures measured while listening to natural speech, without the need of a conventional paper test.

Cortical Tracking of Speech: Toward Collaboration between the Fields of Signal and Sentence Processing

In recent years, a growing number of studies have used cortical tracking methods to investigate auditory language processing. Although most studies that employ cortical tracking stem from the field of auditory signal processing, this approach should also be of interest to psycholinguistics-particularly the subfield of sentence processing-given its potential to provide insight into dynamic language comprehension processes. However, there has been limited collaboration between these fields, which we suggest is partly because of differences in theoretical background and methodological constraints, some mutually exclusive. In this paper, we first review the theories and methodological constraints that have historically been prioritized in each field and provide concrete examples of how some of these constraints may be reconciled. We then elaborate on how further collaboration between the two fields could be mutually beneficial. Specifically, we argue that the use of cortical tracking methods may help resolve long-standing debates in the field of sentence processing that commonly used behavioral and neural measures (e.g., ERPs) have failed to adjudicate. Similarly, signal processing researchers who use cortical tracking may be able to reduce noise in the neural data and broaden the impact of their results by controlling for linguistic features of their stimuli and by using simple comprehension tasks. Overall, we argue that a balance between the methodological constraints of the two fields will lead to an overall improved understanding of language processing as well as greater clarity on what mechanisms cortical tracking of speech reflects. Increased collaboration will help resolve debates in both fields and will lead to new and exciting avenues for research.

Code-Switching Does Not Equal Code-Switching. An Event-Related Potentials Study on Switching From L2 German to L1 Russian at Prepositions and Nouns

Studies on event-related potentials (ERP) in code-switching (CS) have concentrated on single-word insertions, usually nouns. However, CS ranges from inserting single words into the main language of discourse to alternating languages for larger segments of a discourse, and can occur at various syntactic positions and with various word classes. This ERP study examined native speakers of Russian who had learned German as a second language; they were asked to listen to sentences with CS from their second language, German, to their first language, Russian. CS included either a whole prepositional phrase or only the lexical head noun of a prepositional phrase. CS at nouns resulted in a late positive complex (LPC), whereas CS at prepositions resulted in a broad early negativity, which was followed by an anterior negativity with a posterior positivity. Only in the last time window (800–1000 ms) did CS at prepositions result in a broad positivity similar to CS at nouns. The differences between both types of CS indicate that they relate to different psycholinguistic processes.

Progressive Compromise of Nouns and Action Verbs in Posterior Cortical Atrophy

Processing of nouns and action verbs can be differentially compromised following lesions to posterior and anterior/motor brain regions, respectively. However, little is known about how these deficits progress in the course of neurodegeneration. To address this issue, we assessed productive lexical skills in a patient with posterior cortical atrophy (PCA) at two different stages of his pathology. On both occasions, he underwent a structural brain imaging protocol and completed semantic fluency tasks requiring retrieval of animals (nouns) and actions (verbs). Imaging results were compared with those of controls via voxel-based morphometry (VBM), whereas fluency performance was compared to age-matched norms through Crawford's t-tests. In the first assessment, the patient exhibited atrophy of more posterior regions supporting multimodal semantics (medial temporal and lingual gyri), together with a selective deficit in noun fluency. Then, by the second assessment, the patient's atrophy had progressed mainly toward fronto-motor regions (rolandic operculum, inferior and superior frontal gyri) and subcortical motor hubs (cerebellum, thalamus), and his fluency impairments had extended to action verbs. These results offer unprecedented evidence of the specificity of the pathways related to noun and action-verb impairments in the course of neurodegeneration, highlighting the latter's critical dependence on damage to regions supporting motor functions, as opposed to multimodal semantic processes.

Building by Syntax: The Neural Basis of Minimal Linguistic Structures

Language comes in utterances in which words are bound together according to a simple rule-based syntactic computation (merge), which creates linguistic hierarchies of potentially infinite length-phrases and sentences. In the current functional magnetic resonance imaging study, we compared prepositional phrases and sentences-both involving merge-to word lists-not involving merge-to explore how this process is implemented in the brain. We found that merge activates the pars opercularis of the left inferior frontal gyrus (IFG; Brodmann Area [BA] 44) and a smaller region in the posterior superior temporal sulcus (pSTS). Within the IFG, sentences engaged a more anterior portion of the area (pars triangularis, BA 45)-compared with phrases-which showed activity peak in BA 44. As prepositional phrases, in contrast to sentences, do not contain verbs, activity in BA 44 may reflect structure-building syntactic processing, while the involvement of BA 45 may reflect the encoding of propositional meaning initiated by the verb. The pSTS appears to work together with the IFG during thematic role assignment not only at the sentential level, but also at the phrasal level. The present results suggest that merge, the process of binding words together into syntactic hierarchies, is primarily supported by BA 44 in the IFG.

ERPs reveal weaker effects of spelling on auditory rhyme decisions in children than in adults

A classic finding in psycholinguistics is that orthographic form influences the processing of auditory words. The aim of the present study was to examine how reading experience changes this effect. Specifically, we tested the prediction that top-down visual modulation of spoken word recognition is reduced in children compared to adults, owing to their reduced experience with print. Event-related potentials (ERPs) were measured as 8-10-year-old children and adults made rhyme decisions about spoken word pairs that were either orthographically similar or dissimilar. When orthography did not conflict (e.g., throat-boat), both age groups demonstrated a robust rhyme effect marked by greater N400 to no-rhyme versus rhyme trials. For rhyming trials that differed in orthography (e.g., vote-boat) and non-rhyming trials that shared orthography (e.g., warm-farm), adults showed more interference than children. Differences in orthographic interference suggest an extended developmental schedule for top-down mechanisms in speech recognition.

Electrophysiological indices of brain activity to content and function words in discourse

BACKGROUND

An increase in positivity of event-related potentials (ERPs) at the lateral anterior sites has been hypothesized to be an index of semantic and discourse processing, with the right lateral anterior positivity (LAP) showing particular sensitivity to discourse factors. However, the research investigating the LAP is limited; it is unclear whether the effect is driven by word class (function word versus content word) or by a more general process of structure building triggered by elements of a determiner phrase (DP).

AIMS

To examine the neurophysiological indices of semantic/discourse integration using two different word categories (function versus content word) in the discourse contexts and to contrast processing of these word categories in meaningful versus nonsense contexts.

METHODS & PROCEDURES

Planned comparisons of ERPs time locked to a function word stimulus 'the' and a content word stimulus 'cats' in sentence-initial position were conducted in both discourse and nonsense contexts to examine the time course of processing following these word forms.

OUTCOMES & RESULTS

A repeated-measures analysis of variance (ANOVA) for the Discourse context revealed a significant interaction of condition and site due to greater positivity for 'the' relative to 'cats' at anterior and superior sites. In the Nonsense context, there was a significant interaction of condition, time and site due to greater positivity for 'the' relative to 'cats' at anterior sites from 150 to 350 ms post-stimulus offset and at superior sites from 150 to 200 ms post-stimulus offset. Overall, greater positivity for both 'the' and 'cats' was observed in the discourse relative to the nonsense context beginning approximately 150 ms post-stimulus offset. Additionally, topographical analyses were highly correlated for the two word categories when processing meaningful discourse. This topographical pattern could be characterized as a prominent right LAP. The LAP was attenuated when the target stimulus word initiated a nonsense context.

CONCLUSIONS & IMPLICATIONS

The results of this study support the view that the right LAP is an index of general discourse processing rather than an index of word class. These findings demonstrate that the LAP can be used to study discourse processing in populations with compromised metalinguistic skills, such as adults with aphasia or traumatic brain injury.

Brain Responses to World Knowledge Violations: A Comparison of Stimulus- and Fixation-triggered Event-related Potentials and Neural Oscillations

Recent research has shown that brain potentials time-locked to fixations in natural reading can be similar to brain potentials recorded during rapid serial visual presentation (RSVP). We attempted two replications of Hagoort, Hald, Bastiaansen, and Petersson [Hagoort, P., Hald, L., Bastiaansen, M., & Petersson, K. M. Integration of word meaning and world knowledge in language comprehension. Science, 304, 438–441, 2004] to determine whether this correspondence also holds for oscillatory brain responses. Hagoort et al. reported an N400 effect and synchronization in the theta and gamma range following world knowledge violations. Our first experiment (n = 32) used RSVP and replicated both the N400 effect in the ERPs and the power increase in the theta range in the time–frequency domain. In the second experiment (n = 49), participants read the same materials freely while their eye movements and their EEG were monitored. First fixation durations, gaze durations, and regression rates were increased, and the ERP showed an N400 effect. An analysis of time–frequency representations showed synchronization in the delta range (1–3 Hz) and desynchronization in the upper alpha range (11–13 Hz) but no theta or gamma effects. The results suggest that oscillatory EEG changes elicited by world knowledge violations are different in natural reading and RSVP. This may reflect differences in how representations are constructed and retrieved from memory in the two presentation modes.

Anticipation in turn-taking: mechanisms and information sources

During conversations participants alternate smoothly between speaker and hearer roles with only brief pauses and overlaps. There are two competing types of accounts about how conversationalists accomplish this: (a) the signaling approach and (b) the anticipatory (‘projection’) approach. We wanted to investigate, first, the relative merits of these two accounts, and second, the relative contribution of semantic and syntactic information to the timing of next turn initiation. We performed three button-press experiments using turn fragments taken from natural conversations to address the following questions: (a) Is turn-taking predominantly based on anticipation or on reaction, and (b) what is the relative contribution of semantic and syntactic information to accurate turn-taking. In our first experiment we gradually manipulated the information available for anticipation of the turn end (providing information about the turn end in advance to completely removing linguistic information). The results of our first experiment show that the distribution of the participants’ estimation of turn-endings for natural turns is very similar to the distribution for pure anticipation. We conclude that listeners are indeed able to anticipate a turn-end and that this strategy is predominantly used in turn-taking. In Experiment 2 we collected purely reacted responses. We used the distributions from Experiments 1 and 2 together to estimate a new dependent variable called Reaction Anticipation Proportion. We used this variable in our third experiment where we manipulated the presence vs. absence of semantic and syntactic information by low-pass filtering open-class and closed class words in the turn. The results suggest that for turn-end anticipation, both semantic and syntactic information are needed, but that the semantic information is a more important anticipation cue than syntactic information.

ERPs recorded during early second language exposure predict syntactic learning

Millions of adults worldwide are faced with the task of learning a second language (L2). Understanding the neural mechanisms that support this learning process is an important area of scientific inquiry. However, most previous studies on the neural mechanisms underlying L2 acquisition have focused on characterizing the results of learning, relying upon end-state outcome measures in which learning is assessed after it has occurred, rather than on the learning process itself. In this study, we adopted a novel and more direct approach to investigate neural mechanisms engaged during L2 learning, in which we recorded ERPs from beginning adult learners as they were exposed to an unfamiliar L2 for the first time. Learners' proficiency in the L2 was then assessed behaviorally using a grammaticality judgment task, and ERP data acquired during initial L2 exposure were sorted as a function of performance on this task. High-proficiency learners showed a larger N100 effect to open-class content words compared with closed-class function words, whereas low-proficiency learners did not show a significant N100 difference between open- and closed-class words. In contrast, amplitude of the N400 word category effect correlated with learners' L2 comprehension, rather than predicting syntactic learning. Taken together, these results indicate that learners who spontaneously direct greater attention to open- rather than closed-class words when processing L2 input show better syntactic learning, suggesting a link between selective attention to open-class content words and acquisition of basic morphosyntactic rules. These findings highlight the importance of selective attention mechanisms for L2 acquisition.

Marking the counterfactual: ERP evidence for pragmatic processing of German subjunctives

Counterfactual conditionals are frequently used in language to express potentially valid reasoning from factually false suppositions. Counterfactuals provide two pieces of information: their literal meaning expresses a suppositional dependency between an antecedent (If the dice had been rigged…) and a consequent (… then the game would have been unfair). Their second, backgrounded meaning refers to the opposite state of affairs and suggests that, in fact, the dice were not rigged and the game was fair. Counterfactual antecedents are particularly intriguing because they set up a counterfactual world which is known to be false, but which is nevertheless kept to when evaluating the conditional's consequent. In the last years several event-related potential (ERP) studies have targeted the processing of counterfactual consequents, yet counterfactual antecedents have remained unstudied. We present an EEG/ERP investigation which employed German conditionals to compare subjunctive mood (which marks counterfactuality) with indicative mood at the critical point of mood disambiguation via auxiliary introduction in the conditional's antecedent. Conditional sentences were presented visually one word at a time. Participants completed an acceptability judgment and probe detection task which was not related to the critical manipulation of linguistic mood. ERPs at the point of mood disambiguation in the antecedent were compared between indicative and subjunctive. Our main finding is a transient negative deflection in frontal regions for subjunctive compared to indicative mood in a time-window of 450–600 ms. We discuss this novel finding in respect to working memory requirements for rule application and increased referential processing demands for the representation of counterfactuals' dual meaning. Our result suggests that the counterfactually implied dual meaning is processed without any delay at the earliest point where counterfactuality is marked by subjunctive mood.

The fox and the cabra: an ERP analysis of reading code switched nouns and verbs in bilingual short stories

Comprehending a language (or code) switch within a sentence context triggers 2 electrophysiological signatures: an early left anterior negativity post code switch onset - a LAN - followed by a Late Positive Component (LPC). Word class and word position modulate lexico-semantic processes in the monolingual brain, e.g., larger N400 amplitude for nouns than verbs and for earlier than later words in the sentence. Here we test whether the bilingual brain is affected by word class and word position when code switching, or if the cost of switching overrides these lexico-semantic and sentence context factors. Adult bilinguals read short stories in English containing 8 target words. Targets were nouns or verbs, occurred early or late in a story and were presented alternately in English (non-switch) or Spanish (switch) across different story versions. Overall, switched words elicited larger LAN and LPC amplitude than non-switched words. The N400 amplitude was larger for nouns than verbs, more focal for switches than non-switches, and for early than late nouns but not for early than late verbs. Moreover, an early LPC effect was observed only for switched nouns, but not verbs. Together, this indicates that referential elements (nouns) may be harder to process and integrate than relational elements (verbs) in discourse, and when switched, nouns incur higher integration cost. Word position did not modulate the code switching effects, implying that switching between languages may invoke discourse independent processes.

Recurrent temporal networks and language acquisition-from corticostriatal neurophysiology to reservoir computing

One of the most paradoxical aspects of human language is that it is so unlike any other form of behavior in the animal world, yet at the same time, it has developed in a species that is not far removed from ancestral species that do not possess language. While aspects of non-human primate and avian interaction clearly constitute communication, this communication appears distinct from the rich, combinatorial and abstract quality of human language. So how does the human primate brain allow for language? In an effort to answer this question, a line of research has been developed that attempts to build a language processing capability based in part on the gross neuroanatomy of the corticostriatal system of the human brain. This paper situates this research program in its historical context, that begins with the primate oculomotor system and sensorimotor sequencing, and passes, via recent advances in reservoir computing to provide insight into the open questions, and possible approaches, for future research that attempts to model language processing. One novel and useful idea from this research is that the overlap of cortical projections onto common regions in the striatum allows for adaptive binding of cortical signals from distinct circuits, under the control of dopamine, which has a strong adaptive advantage. A second idea is that recurrent cortical networks with fixed connections can represent arbitrary sequential and temporal structure, which is the basis of the reservoir computing framework. Finally, bringing these notions together, a relatively simple mechanism can be built for learning the grammatical constructions, as the mappings from surface structure of sentences to their meaning. This research suggests that the components of language that link conceptual structure to grammatical structure may be much simpler that has been proposed in other research programs. It also suggests that part of the residual complexity is in the conceptual system itself.

The electrophysiological underpinnings of processing gender stereotypes in language

Despite the widely documented influence of gender stereotypes on social behaviour, little is known about the electrophysiological substrates engaged in the processing of such information when conveyed by language. Using event-related brain potentials (ERPs), we examined the brain response to third-person pronouns (lei "she" and lui "he") that were implicitly primed by definitional (passeggera(FEM) "passenger", pensionato(MASC) "pensioner"), or stereotypical antecedents (insegnante "teacher", conducente "driver"). An N400-like effect on the pronoun emerged when it was preceded by a definitionally incongruent prime (passeggera(FEM)--lui; pensionato(MASC)--lei), and a stereotypically incongruent prime for masculine pronouns only (insegnante--lui). In addition, a P300-like effect was found when the pronoun was preceded by definitionally incongruent primes. However, this effect was observed for female, but not male participants. Overall, these results provide further evidence for on-line effects of stereotypical gender in language comprehension. Importantly, our results also suggest a gender stereotype asymmetry in that male and female stereotypes affected the processing of pronouns differently.

Effects of verbal event structure on online thematic role assignment

Event structure describes the relationships between general semantics (Aktionsart) of the verb and its syntactic properties, separating verbs into two classes: telic verbs, which denote change of state events with an inherent end-point or boundary (catch, rescue), and atelic, which refer to homogenous activities (tease, host). As telic verbs describe events, in which the internal argument (Patient) is affected, we hypothesized that processing of telic verb template would activate syntactic position of the Patient during sentence comprehension. Event-related brain potentials (ERPs) were recorded from 20 English speakers, who read sentences with reduced Object relative clauses, in which the verb was either telic or atelic. ERPs in relative clauses diverged on the definite article preceding the Agent: the atelic condition was characterized by larger amplitude negativity at the N100. Such processing differences are explained by activation of the syntactic position for the Patient by the event structure template of telic verbs.

On the early left-anterior negativity (ELAN) in syntax studies

Within the framework of Friederici's (2002) neurocognitive model of sentence processing, the early left anterior negativity (ELAN) in event-related potentials (ERPs) has been claimed to be a brain marker of syntactic first-pass parsing. As ELAN components seem to be exclusively elicited by word category violations (phrase structure violations), they have been taken as strong empirical support for syntax-first models of sentence processing and have gained considerable impact on psycholinguistic theory in a variety of domains. The present article reviews relevant ELAN studies and raises a number of serious issues concerning the reliability and validity of the findings. We also discuss how baseline problems and contextual factors can contribute to early ERP effects in studies examining word category violations. We conclude that--despite the apparent wealth of ELAN data--the functional significance of these findings remains largely unclear. The present paper does not claim to have falsified the existence of ELANs or syntax-related early frontal negativities. However, by separating facts from myths, the paper attempts to make a constructive contribution to how future ERP research in the area of syntax processing may better advance our understanding of online sentence comprehension.

Conflict Resolution in Sentence Processing by Bilinguals

The present study pursues findings from earlier behavioral research with children showing the superior ability of bilinguals to make grammaticality judgments in the context of misleading semantic information. The advantage in this task was attributed to the greater executive control of bilinguals, but this impact on linguistic processing has not been demonstrated in adults. Here, we recorded event-related potentials in young adults who were either English monolinguals or bilinguals as they performed two different language judgment tasks. In the acceptability task, participants indicated whether or not the sentence contained an error in either grammar or meaning; in the grammaticality task, participants indicated only whether the sentence contained an error in grammar, in spite of possible conflicting information from meaning. In both groups, sentence violations generated N400 and P600 waves. In the acceptability task, bilinguals were less accurate than monolinguals, but in the grammaticality task which requires more executive control, bilingual and monolingual groups showed a comparable level of accuracy. Importantly, bilinguals generated smaller P600 amplitude and a more bilateral distribution of activation than monolinguals in the grammaticality task requiring more executive control. Our results show that bilinguals use their enhanced executive control for linguistic processing involving conflict in spite of no apparent advantage in linguistic processing under simpler conditions.

Syntax, concepts, and logic in the temporal dynamics of language comprehension: evidence from event-related potentials

Logic has been intertwined with the study of language and meaning since antiquity, and such connections persist in present day research in linguistic theory (formal semantics) and cognitive psychology (e.g., studies of human reasoning). However, few studies in cognitive neuroscience have addressed logical dimensions of sentence-level language processing, and none have directly compared these aspects of processing with syntax and lexical/conceptual-semantics. We used ERPs to examine a violation paradigm involving "Negative Polarity Items" or NPIs (e.g., ever/any), which are sensitive to logical/truth-conditional properties of the environments in which they occur (e.g., presence/absence of negation in: John hasn't ever been to Paris, versus: John has *ever been to Paris). Previous studies examining similar types of contrasts found a mix of effects on familiar ERP components (e.g., LAN, N400, P600). We argue that their experimental designs and/or analyses were incapable of separating which effects are connected to NPI-licensing violations proper. Our design enabled statistical analyses teasing apart genuine violation effects from independent effects tied solely to lexical/contextual factors. Here unlicensed NPIs elicited a late P600 followed in onset by a late left anterior negativity (or "L-LAN"), an ERP profile which has also appeared elsewhere in studies targeting logical semantics. Crucially, qualitatively distinct ERP-profiles emerged for syntactic and conceptual semantic violations which we also tested here. We discuss how these findings may be linked to previous findings in the ERP literature. Apart from methodological recommendations, we suggest that the study of logical semantics may aid advancing our understanding of the underlying neurocognitive etiology of ERP components.

Tracking lexical access in speech production: electrophysiological correlates of word frequency and cognate effects

The present study establishes an electrophysiological index of lexical access in speech production by exploring the locus of the frequency and cognate effects during overt naming. We conducted 2 event-related potential (ERP) studies with 16 Spanish-Catalan bilinguals performing a picture naming task in Spanish (L1) and 16 Catalan-Spanish bilinguals performing a picture naming task in Spanish (L2). Behavioral results showed a clear frequency effect and an interaction between frequency and cognate status. The ERP elicited during the production of high-frequency words diverged from the low-frequency ERP between 150 and 200 ms post-target presentation and kept diverging until voice onset. The same results were obtained when comparing cognate and noncognate conditions. Positive correlations were observed between naming latencies and mean amplitude of the P2 component following the divergence, for both the lexical frequency and the cognate effects. We conclude that lexical access during picture naming begins approximately 180 ms after picture presentation. Furthermore, these results offer direct electrophysiological evidence for an early influence of frequency and cognate status in speech production. The theoretical implications of these findings for models of speech production are discussed.

CHRONOMETRY OF VISUAL WORD RECOGNITION DURING PASSIVE AND LEXICAL DECISION TASKS: AN ERP INVESTIGATION

In order to investigate the neuroanatomical chronometry of word processing, two experiments using: Event-Related Potentials (ERPs) have been performed. The first one was designed to test the effects of orthographic, phonologic, and lexical properties of linguistic items on the pre-semantic components of ERPs during a passive reading task and massive repetition used to reduce familiarity effect between words and nonwords. In a second study, the level of familiarity was investigated by varying stimulus repetition and frequency in a lexical decision task. Overall results suggest a functional discrimination between orthographic and nonorthographic stimuli begun as early as 170 ms (N170 component) whereas the next components (N230 and N320) were sensitive to the orthographic nature of the stimuli, but also to their lexical/phonologic proprieties. The N320 associated to phonological processing (Bentin et al., 1999) was modulated by word frequency and massive repetition caused its disappearance. This suggests that this component may reflect a nonobligatory phonologic stage of grapheme-phoneme conversion postulated by the DRC model (Coltheart et al., 2001) or semantic phonologically mediated pathway (Harm & Seidenberg, in press).

A comparison of brain activity evoked by single content and function words: an fMRI investigation of implicit word processing

Content and function words have different roles in language and differ greatly in their semantic content. Although previous research has suggested that these different roles may be mediated by different neural substrates, the neuroimaging literature on this topic is particularly scant. Moreover, fMRI studies that have investigated differences between content and function words have utilized tasks that focus the subjects' attention on the differences between these word types. It is possible, then, that task-related differences in attention, working memory, and decision-making contribute to the differential patterns of activation observed. Here, subjects were engaged in a continuous working memory cover task while single, task-irrelevant content and function words were infrequently and irregularly presented. Nonword letter strings were displayed in black font at a fast rate (2/s). Subjects were required to either remember or retrieve occasional nonwords that were presented in colored fonts. Incidental and irrelevant to the memory task, content and function words were interspersed among nonwords at intervals of 12 to 15 s. Both word types strongly activated temporal-parietal cortex, middle and anterior temporal cortex, inferior frontal gyrus, parahippocampal gyrus, and orbital frontal cortex. Activations were more extensive in the left hemisphere. Content words elicited greater activation than function words in middle and anterior temporal cortex, a sub-region of orbital frontal cortex, and the parahippocampal region. Words also evoked extensive deactivation, most notably in brain regions previously associated with working memory and attention.

Syntactic complexity and ambiguity resolution in a free word order language: behavioral and electrophysiological evidences from Basque

In natural languages some syntactic structures are simpler than others. Syntactically complex structures require further computation that is not required by syntactically simple structures. In particular, canonical, basic word order represents the simplest sentence-structure. Natural languages have different canonical word orders, and they vary in the degree of word order freedom they allow. In the case of free word order, whether canonical word order plays any role in processing is still unclear. In this paper, we present behavioral and electrophysiological evidence that simpler, canonical word order preference is found even in a free word order language. Canonical and derived structures were compared in two self-paced reading and one ERPs experiment. Non-canonical sentences required further syntactic computation in Basque, they showed longer reading times and a modulation of anterior negativities and P600 components providing evidence that even in free word order, case-marking grammars, underlying canonical word order can play a relevant role in sentence processing. These findings could signal universal processing mechanisms because similar processing patterns are found in typologically very distant grammars. We also provide evidence from syntactically fully ambiguous sequences. Our results on ambiguity resolution showed that fully ambiguous sequences were processed as canonical sentences. Moreover, when fully ambiguous sequences were forced to complex interpretation by means of the world knowledge of the participants, a frontal negativity distinguished simple and complex ambiguous sequences. Thus the preference of simple structures is presumably a universal design property for language processing, despite differences on parametric variation of a given grammar.

Stuttering and natural speech processing of semantic and syntactic constraints on verbs

PURPOSE

Previous findings from event-related brain potentials (ERPs) indicate that adults who stutter (AWS) exhibit processing differences for visually presented linguistic information. This study explores how neural activations for AWS may differ for a linguistic task that does not require preparation for overt articulation or engage the articulatory loop for silent speech.

METHOD

Syntactic and semantic processing constraints were examined in AWS and adults who are normally fluent (AWNF) by assessment of their behavioral performance and ERPs in a natural speech listening task.

RESULTS

AWS performed similarly to AWNF in identifying verb-agreement violations and semantic anomalies, but ERPs elicited by syntactic and semantic constraints indicated atypical neural functions for AWS. ERPs of the AWNF displayed an expected N400 for reduced semantic expectations and a typical P600 for verb-agreement violations. In contrast, both N400s and P600s for the semantic and verb-agreement conditions were observed in the ERPs of the AWS.

CONCLUSIONS

The findings suggest that AWS may engage semantic-syntactic mechanisms more generally for semantic and syntactic processing. These findings converge with earlier studies using visual stimuli to indicate that whereas linguistic abilities are normal in AWS, underlying brain activity mediating some aspects of language processing may function differently.

The Speed of Orthographic Processing during Lexical Decision: Electrophysiological Evidence for Independent Coding of Letter Identity and Letter Position in Visual Word Recognition

Adults can decide rapidly if a string of letters is a word or not. However, the exact time course of this discrimination is still an open question. Here we sought to track the time course of this discrimination and to determine how orthographic information—letter position and letter identity—is computed during reading. We used a go/no-go lexical decision task while recording event-related potentials (ERPs). Subjects were presented with single words (go trials) and pseudowords (no-go trials), which varied in orthographic conformation, presenting either a double consonant frequently doubled (i.e., “ss”) or never doubled (i.e., “zz”) (identity factor); and a position of the double consonant was which either legal or illegal (position factor), in a 2 × 2 factorial design. Words and pseudowords clearly differed as early as 230 msec. At this latency, ERP waveforms were modulated both by the identity and by the position of letters: The fronto-central no-go N2 was the smallest in amplitude and peaked the earliest to pseudowords presenting both an illegal double-letter position and an identity never encountered. At this stage, the two factors showed additive effects, suggesting an independent coding. The factors of identity and position of double letters interacted much later in the process, at the P3 level, around 300–400 msec on frontal and central sites, in line with the lexical decision data obtained in the behavioral study. Overall, these results show that the speed of lexical decision may depend on orthographic information coded independently by the identity and position of letters in a word.

Processing Pronouns without Antecedents: Evidence from Event-related Brain Potentials

Pronouns that do not have explicit antecedents typically cause processing problems. We investigate a specific example in which this may not be the case, as in “At the interview, they asked really difficult questions,” where the plural pronoun they has no explicit antecedent, yet is intuitively easy to process. Some unspecified but constrained set of individuals (the interview panel or the company) can be inferred as the referent, but it is not crucial to determine specifically which entities are being referred to. We propose that this contrasts with the processing of singular pronouns (he or she), for which it is necessary to determine a specific referent. We used event-related brain potentials to investigate how readers process the pronoun (they vs. he/she) in these cases. Sentences were placed in a context that either did or did not contain an explicit antecedent for the pronoun. There were two key findings. Firstly, when there was no explicit antecedent, a larger fronto-central positivity was observed 750 msec after pronoun onset for he/she than they, possibly reflecting the additional difficulty involved in establishing a referent for he/she than for they when no explicit referent is available. Secondly, there was a larger N400-like deflection evoked by he/she than they, regardless of whether there was an explicit antecedent for the pronoun. We suggest that this is due to the singular pronouns bringing about a greater integration effort than the plural pronoun. This observation adds to a growing body of research revealing fundamental differences in the way these pronouns are handled by the language processor.

An MEG Study of Silent Meaning

Although research on the neural bases of language has made significant progress on how the brain accesses the meanings of words, our understanding of sentence-level semantic composition remains limited. We studied the magnetoencephalography (MEG) responses elicited by expressions whose meanings involved an element not expressed in the syntax, which enabled us to investigate the brain correlates of semantic composition without confounds from syntactic composition. Sentences such as the author began the book, which asserts that an activity was begun although no activity is mentioned in the syntax, were contrasted with control sentences such as the author wrote the book, which involved no implicit meaning. These conditions were further compared with a semantically anomalous condition (the author disgusted the book). MEG responses to the object noun showed that silent meaning and anomaly are associated with distinct effects, silent meaning, but not anomaly, eliciting increased amplitudes in the anterior midline field (AMF) at 350–450 msec. The AMF was generated in ventromedial prefrontal areas, usually implicated for social cognition and theory of mind. Our results raise the possibility that silent meaning interpretation may share mechanisms with these neighboring domains of cognition.

Dependent mechanism of Chinese prepositions processing in the brain: evidence from event-related potentials

OBJECTIVE

To compare the event-related potentials (ERPs) waves of verbs and prepositions in the brain.

METHODS

We recorded ERPs in the brain while participants judged the legality of the collocation for verbs and prepositions.

RESULTS

Both verbs and prepositions elicited a negativity at the frontal site in 230-330 ms and 350-500 ms window. No difference was seen in 230-330 ms and 350-500 ms window; In difference waves, a negativity was elicited in the left and right hemisphere at about 270-400 ms and 470-600 ms window for both open and closed-class words.

CONCLUSION

These may demonstrate that prepositions in modern Chinese are probably not a separate class from verbs and that N280 may be not a specific component for only prepositions (or closed-class words).

The influence of infant diet on early developmental changes in processing human voice speech stimuli: ERP variations in breast and milk formula-fed infants at 3 and 6 months after birth

The purpose of this investigation was to determine if processing of language stimuli during the first half year of life in breast-fed infants differs from that of formula-fed infants. This question was addressed by examining the brain event-related potentials of healthy infants receiving breast milk (n = 15) or milk-based formula (n = 18) recorded in response to consonant vowel syllables presented in an oddball paradigm. The same infants were studied when they were 3-months and 6-months-old. The two groups were comparable on several measures relating to biological and home environment variables previously reported to influence development, including gestation period, birth weight, mother's IQ, and family socioeconomic status, and did not differ in weight or mental or motor development at the times of the visits. In general, ERP response features previously documented in studies of syllable processing in 3-6-month-old infants were observed in this study, including positive components at asymptotically equal to 190 msec (P1), asymptotically equal to 370 msec (P2), and asymptotically equal to 600 msec (P600), and negative components at asymptotically equal to 250 msec (N250), asymptotically equal to 450 msec (N450), and a late, negative going slow wave between 655 and 995 msec (LSW). For both groups there were instances where specific components were either poorly defined, e.g., P1 and N250 to the infrequent syllable at 3 months, N450 and P600 to this syllable at both ages, or not present in many infants, e.g., the P600 to the frequent syllable at 6 months. These variations appeared to be related to individual differences in development or paradigm-related features, i.e., ISI and frequency of syllable occurrence.

The semantic processing of syntactic structure in sentence comprehension: An ERP study

Previous studies have demonstrated that verbs violating selectional constraints of their arguments elicit N400 effects in the event-related potentials (ERPs) in sentence comprehension. The present study examined brain responses to verbs violating semantic constraints specified by syntactic structures (i.e., phrasal constructions), contrasting them with those elicited by lexical-semantic violations between verbs and their arguments. The construction-based semantic violations gave rise to a posterior N400, while the lexical-based semantic violations produced a much stronger N400 with a broader scalp distribution. These findings suggested that the integration of verb meaning with prior sentence context is influenced not only by semantic features of preceding content words with which the verb co-occurs, but also by semantic properties of the syntactic structure in which the verb appears. This study provides online evidence supporting the constructionist approaches to language, which claim that syntactic structures may have their own (abstract) meanings, independent of lexical meanings of their constituent content words.

An ERP study of syntactic processing in English and nonsense sentences

The timecourse of the interaction between syntactic and semantic information during sentence processing in monolingual native English speakers was investigated using event-related potentials (ERPs). To examine the effects of semantic information on syntactic processing, the results for normal English sentences were compared to those for semantically impoverished nonsense (Jabberwocky) sentences. Within each sentence type condition, half of the sentences contained a syntactic violation. Violations elicited a larger amplitude N1 and more negative ERPs around 200 ms after the onset of the critical word relative to the grammatical condition. Although these effects were observed in both sentence types, they were anteriorly distributed for English sentences only. Moreover, the P600 elicited by the syntactic violation was attenuated in processing Jabberwocky as compared to English sentences. These results suggest that semantic and syntactic information are integrated during the earlier stages of syntactic processing indexed by the anterior negativities, and that these interactions continue in the later stages of processing indexed by the P600.

Differential integration efforts of mandatory and optional sentence constituents

We investigated the online sensitivity of the semantic integration system to the different roles played by sentence constituents that are necessary (verbs and nouns) or optional (adjectives) for argument completion. We compared the effect of semantic incongruities introduced in both types of words on the N400 ERP component. Participants read sentences for meaning, half of which were rendered anomalous by an incongruent verb, noun, or an early/late adjective. Incongruent adjectives led to smaller N400 effects than did incongruent nouns and verbs, and the congruity effect for sentence-final adjectives was not significant. All incongruities are therefore not created equal: Incongruent optional sentence constituents create less of an integrative burden than incongruent mandatory sentence constituents, suggesting that online sentence integration processes are sensitive to the distinct roles played by different words in shaping sentence meaning.

Neural correlates of Chinese word-appropriateness judgment: An MEG study

To study the neural correlates of Chinese word-appropriateness judgment, we used 2-word phrases and corresponding meaningless pairs produced by replacing the second words (W2) with homophones. Fourteen right-handed healthy adults viewed word pairs randomly presented one word at a time, and judged the lexical appropriateness of the W2 for combining its preceding first word (W1) into a meaningful phrase. We measured magnetoencephalographic (MEG) responses to W1, appropriate W2, and inappropriate W2 stimuli. For each subject, multi-dipole analyses revealed sequential neuromagnetic activations which involved the bilateral visual cortices at approximately 100 milliseconds (ms), the bilateral occipitotemporal regions at approximately 190 ms, and the left temporal lobe at approximately 350 ms (M350) following stimuli. We found that the word appropriateness had no clear effect on the occipitotemporal activation to W2 stimuli, whereas the M350 activation to inappropriate W2 was greater than that to W1 or appropriate W2. In 8 of our subjects, we found an additional activation in the right temporal region, with a smaller amplitude as compared with the left M350. Our results suggest that the M350 activity reflects both lexical and semantic appropriateness assessment. The lateralized M350 strengths may be used to determine the language dominance hemisphere; and additionally, our 2-word contexture judgment paradigm can be applied in further research on the cortical processing of lexicon-semantic information in Chinese speakers.